'Europe's third oldest stamp' the Double Geneva could bring $185,700

Affixed to one of Switzerlands most important-ever letters, this is the finest example in the world

One of the best preserved examples of a Double Geneva cover will auction at Rapp from its "Special Catalogues"during a two day sale onJune 1-2.

By far the best example of just five known double-combination pairsinthe world, the cover is rightly billed as one of Switzerland's most important-ever letters.

The Double Geneva cover will appear in the first day of Rapp's sale which is, according to organisers, "what, for about half a century, classic Swiss philately has been waiting for.

Special Catalogue #1 features Classic Switzerland Issues dated 1843-1854. Parts of the sale will be devoted todifferent Swiss regions, including Zurich, Geneva, Basle and elsewhere.

The Double Geneva was issued by the City of Geneva, Switzerland in 1843, and is the oldest stamp of the European continent after the Zurich Fours and Sixes (in turn preceded by the New York Dispatch in 1842, and Britain's Penny Black and Twopence Blue in 1840).